An archive device using a large-capacity optical disc (hereinafter referred to as a “disc”) is practically applied. As a memory device in a data center, there is a memory device using a magnetic tape as a medium. Compared to the magnetic tape, a disc is suitable for cold archive intended for long-term storage. For example, Patent Document 1 below discloses an archive device capable of storing 12 discs in a magazine, and the discs can be handled per magazine.
Since the 12 discs are stored in one magazine as disclosed in Patent Document 1, there are advantages that: the number of discs accessible at one time is more increased than in a case of loading discs one by one in a drive; and larger data can be recorded or reproduced at one time. However, it is desired that a larger amount of data is recorded or reproduced in every data center.
The applicant of the present application has previously proposed a disc media storage device (hereinafter referred to as a disc tray as appropriate) that stores a larger number of discs in a casing. This disc tray can store 64 discs (4 rows×16 discs=) in a box-shaped synthetic resin casing having an open upper surface. A large number of the disc trays are stored in a storage rack, and a tray conveyance robot picks out a predetermined disc tray from the storage rack and conveys the disc tray to a disc drive, and the disc drive executes data recording/reproducing for a plurality of discs at the same time.